The present invention relates to an apparatus for recognizing and displaying handwritten characters and figures, and more particularly to the display of stroke information inputted by handwriting and the display of the result of character/figure recognition.
A recognition/display apparatus in which a tablet plate and a display device overlap each other and are united in one body, to display the result of recognition in a printing type form at a place beneath a handwritten character or figure, is disclosed in Japanese patent laid-open specification No. 144,287/83.
In this apparatus, the tablet plate is divided into a plurality of rectangular areas, input strokes are displayed on the display device, and recognition processing is carried out for each rectangular area. Further, when the recognition processing for a rectangular area is completed, the result of recognition is displayed in place of the input strokes in the rectangular area. That is, the strokes in a rectangular area are displayed before recognition, and automatically erased when the recognition processing for the rectangular area is completed.
However, in the case where handwritten characters and figures coexist in a rectangular area, if the subject of the display is changed from all strokes included in the rectangular area to the result of character/figure recognition, there will arise the following problems.
(1) Let us consider the case where characters are handwritten on a line which is part of a figure. In order to erase the strokes of handwritten characters included in a rectangular area, it is required to display the result of recognition processing for the rectangular area, and thus the line in the rectangular area is not displayed. That is, the line in the rectangular area is erased.
(2) When a figure is inputted in the form of strokes and the apparatus is so operated as to display the result of figure recognition, the above strokes displayed on the display device cannot be erased. In more detail, in contrast to character recognition, in figure recognition, each rectangular area is not used as a recognition unit. That is, in order to display only the result of figure recognition, characters which are displayed as a result of recognition, may be erased, and thus it is impossible to erase only strokes which have been used for figure recognition. For this reason, in some cases, the result of figure recognition is displayed while retaining input strokes indicative of a handwritten figure in the display. On the other hand, when all displayed strokes are erased to display the result of figure recognition, even strokes which are not yet used for recognition, are erased. Such an operation is highly objectionable.